You can use the BC in-client designer to add/remove/move UI elements from the SaaS sandbox as well as local docker (I haven't tried it on a full install of BC onprem - MS documentation is stechy on what environments do support and do-not support the designer). The in-client designer is not available for production SaaS environments. Sandbox only for SaaS.
https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-inclient-designer
Keep in mind that for SaaS, this means that while you can design the sandbox UI without visual studio code, and consequently download the source code for the .app that designer creates under the hood, you still need to leverage VS Code to promote those changes to production.
For SaaS, using VS Code is unavoidable.